async function async1() {
    console.log(1);
    await async2();
    console.log("AAA");
}

// 此处发生状态吸收后会有两个任务进入微队列
/*async*/
function async2() {
    return Promise.resolve(2);
}

async1();

Promise.resolve()
    .then(() => console.log(3))
    .then(() => console.log(4))
    .then(() => console.log(5));

